The present invention relates to methods and apparatuses for using, cleaning and maintaining electrically heated cigarette smoking systems.
Commonly assigned U.S. Pat. Nos. 5,388,594; 5,505,214; 5,530,225; and 5,591,368 disclose various electrically powered smoking systems comprising cigarettes and electric lighters and are hereby expressly incorporated herein by reference.
The above-referenced smoking systems are designed with the intention of providing the smoker with all the pleasures of smoking while significantly reducing the side stream smoke produced during smoking. The smoking system also allows smokers the added benefit of reinitiating smoking of a cigarette that has been partially smoked, thereby providing the smoker with the ability to suspend and reinitiate smoking as desired.
In the operation of the smoking system, condensates may form and collect on the various parts of the heating fixture of the smoking device. The build up of condensates is undesirable as it affects the functionality of the smoking device and the flavor and overall pleasure a smoker of the device may have. Therefore, it is desirable to periodically clean the heating elements and other metallic components of the smoking device in order to remove the condensates that may have accumulated on the components.
Commonly assigned U.S. Pat. No. 6,119,700, discloses a cleaning system that is separate from the smoking device. The cleaning system provides two embodiments for cleaning the condensates from the heating fixture. The first embodiment utilizes a brush that fits within the heating element and cleans the collected condensates. The second embodiment utilizes an aqueous solution that when flushed through the device cleans out the foreign condensates that have accumulated. In using this cleaning device the heating element must be removed from the smoking device which can be time consuming for the smoker.
U.S. Pat. No. 5,878,752, issued Mar. 9, 1999, hereby incorporated by reference, discloses an electrical lighter that has an internal sleeve, or xe2x80x9csecondary canxe2x80x9d or xe2x80x9csecondary heaterxe2x80x9d which concentrically surrounds the cigarette heating fixture. The cigarette heater elements transfer heat primarily via conduction to the inner surface of the sleeve and indirectly from this heated inner surface primarily via convection and radiation to other component surfaces to volatilize condensates which are deposited thereon during smoking. However, activation of the heating elements may not fully clean the condensates located on other components within the device. A ceramic layer is deposited on the outer surface of the sleeve to electrically insulate a subsequently applied sleeve heating element from the metal sleeve except for an exposed negative contact. In an alternative embodiment, an induction coil for heating the sleeve is shown.
The use of non-conventional smoking devices is increasing. Therefore, it is desirable to provide a fast and efficient means for cleaning the devices of the condensates which accumulate during smoking, thus providing further convenience and enjoyment for the smoker.
The present invention provides methods and apparatus that utilize inductive heating to thermally clean condensates from the surface of the components located within a smoking device. The inductive heating process is performed using radio frequency excitation coils which are wound in a desired configuration around the components that are to be directly heated, with power being provided to the coils in a controlled manner that achieves resonant circuit conditions. In embodiments of the invention, the arrangement of the coils creates a thermal wave that travels along the components that are being thermally cleaned. The temperature of the heated components within the smoking device is controlled by a control system. The control system utilizes measured temperature information of the components and adjusts the power to the coils and/or the airflow within the smoking device to control the temperature.
In other embodiments of the invention, a unique cylindrical cannister, which is positioned around the heater blades of the smoking device, is utilized to localize heating regions within the smoking device. Further embodiments utilize a catalyst which aids in reducing the amount of condensates and particles in the residue created when a tobacco product is ignited within the smoking device.